Selecting The V/F Characteristic - Siemens Sinamics G120P Operating Instructions Manual

Functions
7.5 Motor control
The value of the motor voltage at the rated motor frequency also depends on the following
variables:
● Ratio between the inverter size and the motor size
● Line voltage
● Line impedance
● Actual motor torque
7.5.3.2

Selecting the V/f characteristic

Procedure
Proceed as follows to select a V/f characteristic in STARTER:
1. Go online.
2. Select the V/f characteristic curve in one of the screen forms "Speed closed-loop
controller" or "V/f control".
Proceed as follows to select a V/f characteristic with the IOP:
1. Select the "Parameters" menu.
2. Select "Expert" as parameter filter.
3. Select parameter p1300.
4. Set p1300 to the appropriate value.
Table 7- 21 Linear and parabolic characteristics
Requirement Application examples
The required Eccentric-worm pump,
torque is inde- compressor
pendent of the
speed
The required Centrifugal pumps,
torque increases radial fans, axial fans,
with the speed compressors
362
Remark
-
The inverter equalizes the voltage drops
across the stator resistance.
Precondition: You have set the motor data
according to the type plate and have per-
formed the motor identification after the
basic commissioning.
Lower losses in the motor and inverter
than for a linear characteristic.
Characteristic
Linear
Linear with Flux
Current Control
(FCC)
Parabolic
Inverter cabinet units
Operating Instructions, 12/2014, A5E32923362A
Parameter
p1300 = 0
p1300 = 1
p1300 = 2